3,536 research outputs found
Compatible finite element methods for numerical weather prediction
This article takes the form of a tutorial on the use of a particular class of
mixed finite element methods, which can be thought of as the finite element
extension of the C-grid staggered finite difference method. The class is often
referred to as compatible finite elements, mimetic finite elements, discrete
differential forms or finite element exterior calculus. We provide an
elementary introduction in the case of the one-dimensional wave equation,
before summarising recent results in applications to the rotating shallow water
equations on the sphere, before taking an outlook towards applications in
three-dimensional compressible dynamical cores.Comment: To appear in ECMWF Seminar proceedings 201
HATCHLING SEX RATIOS AND LOCOMOTOR PERFORMANCE OF MIDLAND PAINTED TURTLES (CHRYSEMYS PICTA MARGINATA)
The primary objectives of this study were to understand how canopy cover and nest temperatures affect hatchling sex ratios and locomotor performance (i.e., swimming sprint speed and righting response) of Chrysemys picta marginata nests. Seventeen nests were monitored with temperature data-loggers during the 2009 nesting season and found to contain 100% male-biased clutches with a mean nest temperature range of 20.0–24.0°C during the thermosensitive period (TSP). The percentage of canopy cover over each nest was inversely and significantly correlated with mean nest temperatures experienced during the TSP. Mean nest temperatures (MNT) did not have a statistical effect on either measure of locomotor performance; however, there was an observed trend toward increased performance with increased MNT
Higher-order compatible finite element schemes for the nonlinear rotating shallow water equations on the sphere
We describe a compatible finite element discretisation for the shallow water
equations on the rotating sphere, concentrating on integrating consistent
upwind stabilisation into the framework. Although the prognostic variables are
velocity and layer depth, the discretisation has a diagnostic potential
vorticity that satisfies a stable upwinded advection equation through a
Taylor-Galerkin scheme; this provides a mechanism for dissipating enstrophy at
the gridscale whilst retaining optimal order consistency. We also use upwind
discontinuous Galerkin schemes for the transport of layer depth. These
transport schemes are incorporated into a semi-implicit formulation that is
facilitated by a hybridisation method for solving the resulting mixed Helmholtz
equation. We illustrate our discretisation with some standard rotating sphere
test problems.Comment: accepted versio
The Microbiota and Health Promoting Characteristics of the Fermented Beverage Kefir
peer-reviewedKefir is a complex fermented dairy product created through the symbiotic fermentation of milk by lactic acid bacteria and yeasts contained within an exopolysaccharide and protein complex called a kefir grain. As with other fermented dairy products, kefir has been associated with a range of health benefits such as cholesterol metabolism and angiotensin-converting enzyme (ACE) inhibition, antimicrobial activity, tumor suppression, increased speed of wound healing, and modulation of the immune system including the alleviation of allergy and asthma. These reports have led to increased interest in kefir as a focus of research and as a potential probiotic-containing product. Here, we review those studies with a particular emphasis on the microbial composition and the health benefits of the product, as well as discussing the further development of kefir as an important probiotic product.The authors are funded through the Teagasc Walsh Fellowship Scheme(2014025)and internal Teagasc funding(RMIS6486). BW is supported by the Canada Research Chairs Program and research in the Cotter laboratory is funded by SFI through the PI award “Obesibiotics”(11/PI/1137)and in the form of a center grant (APC Microbiome Institute Grant Number SFI/12/RC/2273)
Computerized Evaluation of Individual State Modules
A report on the May 22, 1969 meeting of Appalachian Adult Basic Education Demonstration Center held in Lexington, Kentucky compiled by Jude T. Cotter
Point-of-Use Arsenic Treatment Using Activated Alumina
Effective and affordable arsenic removal from drinking water has become a significant issue recently. The United States Environmental Protection Agency (EPA) has promulgated a new maximum contaminant level (MCL) for arsenic in drinking water which will take effect in January 2004. The current arsenic MCL of 50 micrograms per liter (ugll) was set by the United sates Public Health Service in 1943 and has not been reduced in nearly 60 years. Arsenic has been linked to various types of cancers, prompting EPA to change the standard. Due to the fact many water systems, especially small water utilities serving less than 10,000 people, will be impacted by a reduced standard much research is currently being done to fmd treatment technologies affordable enough for small water systems to implement and maintain. Many small water utilities lack the financial and technical resources required to construct and maintain centrally located water treatment facilities capable of removing arsenic. For this reason, many small water systems are exploring the option of using point-of-use (POU) systems. POU systems are typically installed under kitchen sinks and provide water from a separate tap to meet daily drinking and cooking needs. Several types ofPOU systems are readily available from various retailers. Reverse osmosis POU systems are the most common. There are also several types of POU filtration systems that utilize the adsorption process to remove organic contaminants from drinking water. Most POU filtration systems are designed to remove contaminants associated with taste and odor problems. None are specifically designed to remove arsenic. This project evaluated a POU filtration/adsorption system utilizing Activated Alumina FS-50 (AA FS-50). The POU system used for this project was fabricated from components of common home water treatment devices. The system was evaluated for perfonnance, affordability, longevity and applicability. State and federal regulations govern the use of POD water treatment systems. Strict rules must be followed by water systems utilizing POU systems. Possibly, residents of communities employing POU water treatment could perfonn the necessary maintenance required to keep the systems in compliance. This would reduce maintenance costs, making POD treatment more affordable, but current regulations would need to be changed. Data gathered during the study indicates effective arsenic removal by the system for 4,000 bed volumes (1 bed volume =lliter). Under nonnal operating conditions spent cartridges would only need to be replaced every 6-8 months. Manufacturing, installation and maintenance costs associated with the system may make it an effective and affordable treatment option for some small water systems
Growth and peroxidase production in cultures of horseradish (Armoraciu mticunu).
Peroxidase, an enzyme of commercial importance to the
diagnostic industry, is currently extracted and purified from
the roots of field-grown horseradish plants (Armoracia rusticana)
by conventional methods. It is, however, known that
plant peroxidases occur in undifferentiated cells maintained
in culture at a specific and total activity which may surpass
that of the root (Shinshi & Noguchi, 1976). In this report we
have examined cell cultures of the horseradish plant as a
source of the enzyme
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